Propolis has anti-inflammatory, analgesic and healing properties. The purpose of this study was to determine whether a gel containing 2% of propolis extract, 0.2% of ascorbic acid and 0.2% of tocopherol acetate is effective in preventing surgical complications related to impacted lower third molar extractions. A randomized, double-blind, split-mouth study was performed. Fifteen patients were recruited who needed bilateral impacted lower third molar extractions with a similar surgical difficulty. A test or placebo gel was administered randomly inside post-extraction sockets. Each patient was instructed to apply the gel 3 times/day in the surgical wound for a week. After a month, the contralateral third molar was extracted, and the opposite gel applied. The following parameters were diagnosed/evaluated and then recorded: alveolar osteitis following Blum?s criteria, swelling and trismus at day one, two, three and seven post-intervention, wound healing at day 7 post-intervention, and postoperative pain using a visual analog scale, as well as, the number of analgesic pill intake. A total of twenty-six surgical procedures were performed in 13 patients (mean age 20.67±2 years). Alveolar osteitis was reported in 3 patients from the placebo group (23.1%) and none in the test group (0%) (p=0.25). No statistically significant differences were reported in swelling, trismus, wound healing or analgesic pill consumption between two groups. But statistically lower postoperative pain during the 7 days after surgical extractions was found according to visual analog scale in test group compared to the placebo group (p=0.007). No side effects were reported. The application of this gel may be effective in preventing alveolitis and thus reducing postoperative pain after impacted third molar extractions. More randomized clinical trials with larger sample are needed to confirm these results.